Hilary and Haylie Duff are living in a material world, and they are going to be material girls — in their first movie together, that is.

The famous sibs have already teamed up for one '80s cover for a film this year (the Go-Go's' 1981 classic "Our Lips Are Sealed" for the soundtrack to "A Cinderella Story"), and now they have their sights set on another: Madonna's 1984 hit "Material Girl" for the soundtrack to the like-named comedy "Material Girls," in which they'll co-star.

The Duffs will play sibling heiresses who lose their father's fortune in the wake of a scandal and are forced to fend for themselves in the real world. There are shades of the Hilton sisters not just in the setup, but also in their characters' improbable but distinctive names, Persia and Tanzie. This "riches-to-rags" tale originally attracted interest from Anne Hathaway and Lindsay Lohan.

Producers are currently deciding on a director, and the script is going through one more rewrite. The film is scheduled to begin shooting in January. As for that song the Duffs have in mind, thanks to the fact that the film is being produced by Madonna's Maverick Films, permission probably won't be much of a problem. However, reps for both sisters caution that as far as the cover of "Material Girl" is concerned, everything is still being negotiated, and nothing has been signed just yet.

In addition to their cover of "Our Lips Are Sealed," the Duff sisters have collaborated before, working on Hilary's albums together and touring as a package deal this past summer (see [article id="1489742"]"Hilary Duff Shows A 'Girl Can Rock' — Safely — At New York Show"[/article]). While Hilary has the higher profile in the film world, Haylie received rave reviews as a popular high school brat in "Napoleon Dynamite" this summer.